Safety systems for vehicles have evolved through the years and have been improved upon by enhancements such as intervention into the suspension, steering, brakes, or engine management of the driving engine for the vehicle. Such enhancements include: traction slip control to prevent the spinning of the wheels of the vehicle, brake force proportioning to regulate the ratio of brake forces between the front axle and rear axle of the vehicle, anti-lock brakes, and electronic stability control which can affect driving conditions of the vehicle during yawing of the vehicle about its vertical axis.
In electronic stability control systems for vehicles, it is necessary to be able to assess the behavior of the vehicle, particularly if the assessment and any response can be accomplished in real time. These systems that assess vehicle motion, accomplish this assessment in real time and rely on the ability to monitor the movements of the vehicle by installing sensors to measure the acceleration of the vehicle and the angular rotational rates of the vehicle.
During normal driving, the vehicle responds to the driver's commands, and the driver maintains control of the vehicle. However, if the driver operates the vehicle beyond his/her limits or even the limits of the vehicle, the vehicle can exhibit a spin response as a yaw movement in excess of that required for the situation, or a plow response as a yaw movement less than that required for the situation. A system such as the Electronic Stability Program (ESP) can provide some correction to the motions of the vehicle in certain situations by using mathematical models that consider the vehicle dynamics and forces of the tires of the vehicle along with measurements supplied by sensors recording vehicle speed, yaw rate, and actions of the driver of the vehicle, such as the steering wheel and the application of the brakes and accelerator.
However, the use of Electronic Stability Program mathematical models can have some limitations with respect to how much a motion can be corrected or whether a driver will respond appropriately. In addition, such systems function by observing movements of the body of the vehicle, only, and do not extend to any auxiliary vehicle, such as a trailer connected to the vehicle. Accordingly, all forces affecting the performance of a combination vehicle and trailer would not be included in the mathematical model of the Electronic Stability Program as the information is gathered from the vehicle, only. Also, many of the existing Electronic Stability Program systems do not include determinations of whether a trailer is attached to the tow-vehicle.
Thus, a need exists for an electronic stability enhancing system that can include direct assessment, response, and multiple actions applied in real time and based upon determinations of driver inputs of the vehicle towing the trailer assembly along with direct measurements of forces and motions as well as calculated responses using information gathered from the tow-vehicle connected to the trailer assembly.
Further, a need exists for an electronic stability enhancing system, that uses a model, which includes the tow-vehicle and the trailer assembly, such that the computer instructions of the electronic stability enhancing system can be used in determining a direct response for optimizing the performance of the tow-vehicle and trailer assembly combination. Such a system can provide for an improved optimization of the electronic stability control system for the vehicle when the vehicle is pulling a trailer.
The present embodiments of the invention meet these needs.